Kal,

I'm not sure I understand your requirements.
With COMMAND mode, you cannot update several keys (i.e. rows) atomically: you must send update events for one key at a time.
Only in case you are providing the initial snapshot, you can take advantage of the end-of-snapshot signal: your Data Adapter, after sending all lines related with the snapshot (that is, one ADD command, with <is snapshot> set as true, for each row which is included in the initial state) can send a
<timestamp>|EOS|S|<item name>|S|<ID>
line. In this way, your client custom code will receive a corresponding notification and this allows it to cache the snapshot lines and process them atomically when all of them have been collected (if this is your case, we can expand on this point).
May you please provide an example of an operation which may not fit in this protocol?

Dario